Contamination of blood supplies with infectious microorganisms such as malaria, West Nile virus, HIV, hepatitis and other viruses and bacteria presents a serious health hazard for those who must receive transfusions of whole blood or administration of various blood components such as platelets, red cells, blood plasma, Factor VIII, plasminogen, fibronectin, anti-thrombin III, cryoprecipitate, human plasma protein fraction, albumin, immune serum globulin, prothrombin complex, plasma growth hormones, and other components isolated from blood. Blood screening procedures may miss contaminants, and sterilization procedures which do not damage cellular blood components but effectively inactivate all infectious viruses and other microorganisms have not heretofore been available. In addition, a system that uses the same chemistry to inactivate microorganisms in different fluids, for example separate blood components, is desired for many reasons, including ease of use in a blood bank setting. This type of system has not heretofore been available. It is also desired that the inactivation treatment be easily implemented in a blood bank setting, and produce inactivation in a short period of time.
Malaria is an infectious disease caused by protozoan parasites of the Plasmodium genera. The species that cause malaria in humans are: P. falciparum (most malignant), P. vivax, P. malariae, and P. ovale (Mims, C A, et al. Medical Microbiology 1993; London: Mosby: 30.8–30.9). Plasmodium parasites are spread by the female anopheles mosquito, which transmits the infection to various primates and to non-immune human hosts (Boyd R F. Clinical parasitology. In Basic Medical Microbiology, 1995; Boston: Little, Brown and Company:513–514). Donated blood is not tested for infection with malaria, although there are no means to completely prevent the transmission of malaria by blood transfusion (Shulman I. Transmission of parasitic infections by blood transfusion. In Principles of transfusion medicine, eds. E C. Rossi, T L. Simon, G L. Moss, S A. Gould, 1996; Baltimore: Williams and Wilkins:733–8). In the United States, the risk of transfusion-transmitted malaria is limited by excluding blood donors who have traveled to malaria-endemic areas. This results in the deferral of 70,000 donors a year (Nahlen B L, et al. Reassessment of blood donor selection criteria for United States travelers to malarious areas. Transfusion. 1991; 31:798–804). In countries with a high prevalence of malaria infection, deferral of donors may not be an option. A method for the inactivation of malaria parasites in blood may mitigate the risk of transfusion transmission from donors that are not removed through ordinary screening methods, and may allow the military to use donors that had been stationed in malaria-endemic areas. Such a method may also reduce the risk of transfusion-transmitted malaria in countries where large portions of the donor population have been exposed to the parasite.
West Nile Virus has recently entered the United States and causes a variety of illnesses, including West Nile encephalitis, West Nile meningitis and West Nile meningoencephalitis. West Nile virus is transmitted through mosquitoes and birds. West Nile virus is known to be transmitted through transfusion of blood products from infected individuals (<http://www.cdc.gov/ncidod/dvbid/westnile/qa/transfusion.htm>). Currently, blood is not tested for West Nile virus and exclusion of donors who are believed to be infected with the West Nile Virus is the only method used to prevent the spread of West Nile virus through blood transfusions. However, most people who are infected with the West Nile Virus do not show symptoms and may not be excluded from the donation process, therefore, transmitting the virus through transfused blood.
There are several reported methods of decontaminating blood. Solvent detergent methods of blood component decontamination work by dissolving phospholipid membranes surrounding viruses such as HIV, and do not damage protein components of blood; however, if blood cells are present, such methods cannot be used because of damage to cell membranes.
The use of photosensitizers, compounds which absorb light of a defined wavelength and transfer the absorbed energy to an energy acceptor, has been proposed for blood component sterilization. For example, European Patent application 196,515 published Oct. 8, 1986, suggests the use of non-endogenous photosensitizers such as porphyrins, psoralens, acridine, toluidines, flavine (acriflavine hydrochloride), phenothiazine derivatives, and dyes such as neutral red and methylene blue, as blood additives. Protoporphyrin, which occurs naturally within the body, can be metabolized to form a photosensitizer; however, its usefulness is limited in that it degrades desired biological activities of proteins. Chlorpromazine is also exemplified as one such photosensitizer; however its usefulness is limited by the fact that it should be removed from any fluid administered to a patient after the decontamination procedure because it has a sedative effect.
Goodrich, R. P., et al. (1997), “The Design and Development of Selective, Photoactivated Drugs for Sterilization of Blood Products,” Drugs of the Future 22:159–171 provides a review of some photosensitizers including psoralens, and some of the issues of importance in choosing photosensitizers for decontamination of blood products. The use of texaphyrins for DNA photocleavage is described in U.S. Pat. No. 5,607,924 issued Mar. 4, 1997 and U.S. Pat. No. 5,714,328 issued Feb. 3, 1998 to Magda et al. The use of sapphyrins for viral deactivation is described in U.S. Pat. No. 5,041,078 issued Aug. 20, 1991 to Matthews, et al. Inactivation of extracellular enveloped viruses in blood and blood components by Phenthiazin-5-ium dyes plus light is described in U.S. Pat. No. 5,545,516 issued Aug. 13, 1996 to Wagner. The use of porphyrins, hematoporphyrins, and merocyanine dyes as photosensitizing agents for eradicating infectious contaminants such as viruses and protozoa from body tissues such as body fluids is disclosed in U.S. Pat. No. 4,915,683 issued Apr. 10, 1990 and related U.S. Pat. No. 5,304,113 issued Apr. 19, 1994 to Sieber et al. The mechanism of action of such photosensitizers is described as involving preferential binding to domains in lipid bilayers, e.g. on enveloped viruses and some virus-infected cells. Photoexcitation of membrane-bound agent molecules leads to the formation of reactive oxygen species such as singlet oxygen which causes lipid peroxidation. A problem with the use of such photosensitizers is that they attack cell membranes of desirable components of fluids to be decontaminated, such as red blood cells, and the singlet oxygen also attacks desired protein components of fluids being treated. U.S. Pat. No. 4,727,027 issued Feb. 23, 1988 to Wiesehahn, G. P., et al. discloses the use of furocoumarins including psoralen and derivatives for decontamination of blood and blood products, but teaches that steps must be taken to reduce the availability of dissolved oxygen and other reactive species in order to inhibit denaturation of biologically active proteins.
Photoinactivation of viral and bacterial blood contaminants using halogenated coumarins is described in U.S. Pat. No. 5,516,629 issued May 14, 1996 to Park, et al. U.S. Pat. No. 5,587,490 issued Dec. 24, 1996 to Goodrich Jr., R. P., et al. and U.S. Pat. No. 5,418,130 to Platz, et al. disclose the use of substituted psoralens for inactivation of viral and bacterial blood contaminants. The latter patent also teaches the necessity of controlling free radical damage to other blood components. U.S. Pat. No. 5,654,443 issued Aug. 5, 1997 to Wollowitz et al. teaches new psoralen compositions used for photodecontamination of blood. U.S. Pat. No. 5,709,991 issued Jan. 20, 1998 to Lin et al. teaches the use of psoralen for photodecontamination of platelet preparations and removal of psoralen afterward. U.S. Pat. No. 5,120,649 issued Jun. 9, 1992 and related U.S. Pat. No. 5,232,844 issued Aug. 3, 1993 to Horowitz, et al., also disclose the need for the use of “quenchers” in combination with photosensitizers which attack lipid membranes, and U.S. Pat. No. 5,360,734 issued Nov. 1, 1994 to Chapman et al. also addresses the problem of prevention of damage to other blood components.
Photosensitizers which attack nucleic acids are known to the art. U.S. Pat. No. 5,342,752 issued Aug. 30, 1994 to Platz et al. discloses the use of compounds based on acridine dyes to reduce parasitic contamination in blood matter comprising red blood cells, platelets, and blood plasma protein fractions. These materials, although of fairly low toxicity, do have some toxicity e.g. to red blood cells. This patent fails to disclose an apparatus for decontaminating blood on a flow-through basis. U.S. Pat. No. 5,798,238 to Goodrich, Jr., et al., discloses the use of quinolone and quinolone compounds for inactivation of viral and bacterial contaminants.
Binding of DNA with photoactive agents has been exploited in processes to reduce lymphocytic populations in blood as taught in U.S. Pat. No. 4,612,007 issued Sep. 16, 1986 and related U.S. Pat. No. 4,683,889 issued Aug. 4, 1987 to Edelson.
Riboflavin (7,8-dimethyl-10-ribityl isoalloxazine) has been reported to attack nucleic acids. Photoalteration of nucleic acid in the presence of riboflavin is discussed in Tsugita, A, et al. (1965), “Photosensitized inactivation of ribonucleic acids in the presence of riboflavin,” Biochimica et Biophysica Acta 103:360–363; and Speck, W. T. et al. (1976), “Further Observations on the Photooxidation of DNA in the Presence of Riboflavin,” Biochimica et Biophysica Acta 435:39–44. Binding of lumiflavin (7,8,10-trimethylisoalloxazine) to DNA is discussed in Kuratomi, K., et al. (1977), “Studies on the Interactions between DNA and Flavins,” Biochimica et Biophysica Acta 476:207–217. Hoffmann, M. E., et al. (1979), “DNA Strand Breaks in Mammalian Cells Exposed to Light in the Presence of Riboflavin and Tryptophan,” Photochemistry and Photobiology 29:299–303 describes the use of riboflavin and tryptophan to induce breaks in DNA of mammalian cells after exposure to visible fluorescent light or near-ultraviolet light. The article states that these effects did not occur if either riboflavin or tryptophan was omitted from the medium. DNA strand breaks upon exposure to proflavine and light are reported in Piette, J. et al. (1979), “Production of Breaks in Single- and Double-Stranded Forms of Bacteriophage ΦX174 DNA by Proflavine and Light Treatment,” Photochemistry and Photobiology 30:369–378, and alteration of guanine residues during proflavine-mediated photosensitization of DNA is discussed in Piette, J., et al. (1981), “Alteration of Guanine Residues during Proflavine Mediated Photosensitization of DNA,” Photochemistry and Photobiology 33:325–333.
J. Cadet, et al. (1983), “Mechanisms and Products of Photosensitized Degradation of Nucleic Acids and Related Model Compounds,” Israel J. Chem. 23:420–429, discusses the mechanism of action by production of singlet oxygen of rose bengal, methylene blue, thionine and other dyes, compared with mechanisms not involving production of singlet oxygen by which nucleic acid attack by flavin or pteron derivatives proceeds. Riboflavin is exemplified in this disclosure as having the ability to degrade nucleic acids. Korycka-Dahl, M., et al. (1980), “Photodegradation of DNA with Fluorescent Light in the Presence of Riboflavin, and Photoprotection by Flavin Triplet-State Quenchers,” Biochimica et Biophysica Acta 610:229–234 also discloses that active oxygen species are not directly involved in DNA scission by riboflavin. Peak, J. G., et al. (1984), “DNA Breakage Caused by 334-nm Ultraviolet Light is Enhanced by Naturally Occurring Nucleic Acid Components and Nucleotide Coenzymes,” Photochemistry and Photobiology 39:713–716 further explores the mechanism of action of riboflavin and other photosensitizers. However, no suggestion is made that such photosensitizers be used for decontamination of medical fluids.
Addition of riboflavin to in vitro cultures of P. falciparum has been reported to inhibit asexual parasite growth (Akompong, T., et al. In Vitro Activity of Riboflavin against the Human Malaria Parasite Plasmodium falciparum., Antimicrob Agents Chemother, January 2000; 44: 88–96) and kill gametocytes (Akompong, T., et al. Gametocytocidal Activity and Synergistic Interactions of Riboflavin with Standard Antimalarial Drugs against Growth of Plasmodium falciparum In Vitro. Antimicrob Agents Chemother, November 2000; 44: 3107–3111). Riboflavin, when added to cultures in the asexual stage in combination with antimalarial drugs, was reported to enhance the drug activity (Akompong, T., et al. Gametocytocidal Activity and Synergistic Interactions of Riboflavin with Standard Antimalarial Drugs against Growth of Plasmodium falciparum In Vitro. Antimicrob Agents Chemother, November 2000; 44: 3107–3111). In earlier works (Das B S, et al. Riboflavin deficiency and severity of malaria, Eur J Clin Nutr, 1988 April; 42:277–83; Dutta P. Enhanced uptake and metabolism of riboflavin in erythrocytes infected with Plasmodium falciparum. J Protozool 1991 September–October; 38:479–83), riboflavin deficiency was observed to be detrimental to the parasite. The use of riboflavin as a photosensitizer to treat blood and blood components that may have malaria infection has not been reported.
Apparatuses for decontamination of blood have been described in U.S. Pat. No. 5,290,221 issued Mar. 1, 1994 to Wolfe, Jr., et al. and U.S. Pat. No. 5,536,238 issued Jul. 16, 1996 to Bischof. U.S. Pat. No. 5,290,221 discloses the irradiation of fluid in a relatively narrow, arcuate gap. U.S. Pat. No. 5,536,238 discloses devices utilizing optical fibers extending into a filtration medium. Both patents recommend as photosensitizers benzoporphryin derivatives which have an affinity for cell walls.
U.S. Pat. No. 5,527,704 issued Jun. 18, 1996 to Wolf, Jr., et al. discusses an apparatus to inactivate viruses contained in a body fluid in a container using methylene blue as a photosensitizer. The body fluid is maintained in a static state within the container during irradiation. U.S. Pat. No. 5,868,695 issued Feb. 9, 1999 to Wolf, Jr. et al. discloses a system where blood containing a photoactive material is directed in a predetermined flow path such as a serpentine in a narrow gap in a treatment chamber. PCT published application No. WO 96/06647 discloses irradiating a product in an array of light emitting diodes surrounded by a fluid used to prevent overheating of the diodes. Riboflavin and UV light inactivate viruses and bacteria in plasma and platelet products (Samar, R, et al. Poster, Viral Inactivation in Plasma Using Riboflavin-Based Technology. AABB 54th Annual Meeting. November 2001; Goodrich R P. The use of riboflavin for the inactivation of pathogens in blood products. Vox Sang. 2000; 78 (suppl 2):211–15). Riboflavin and visible light provide demonstrated virus inactivation in platelets (Goodrich, L, et al. Poster. Riboflavin Pathogen Inactivation Process Yields Good Platelet Cell Quality and Expedient Viral Kill. ASH 43rd Annual Meeting. December 2001) and in red cell suspensions (McAteer M J, et al. Poster: Photo-inactivation of virus in packed red blood cell units using riboflavin and visible light. AABB 53rd Annual Meeting. November 2000).
Sterilization procedures which do not damage cellular blood components but effectively inactivate infectious viruses and other microorganisms and contaminants are disclosed in U.S. Pat. Nos. 6,258,577, 6,277,337, 6,268,120 and PCT publications WO 01/28599, WO 00/04930. Storage solutions containing photosensitizers are disclosed in U.S. patent application Ser. No. 09/725,426 and U.S. patent application Ser. No. 09/596,429.
There is a need for an inactivation procedure for West Nile virus and malaria, as well as other microorganisms that are not detected in blood products.
All references, publications, patents and patent applications referred to herein are hereby incorporated by reference to the extent not inconsistent with the disclosure herewith.